Peak Dobutamine Stress Echocardiography Research Articles

107 Low-flow low-gradient aortic stenosis: aortic valve area estimated by continuity equation versus simplified method of projected aortic valve area

Abstract Introduction The evaluation of real severity of "low-flow low-gradient" aortic stenosis (LFLG AS) is particularly challenging. TOPAS study demonstrated that projected aortic valve area at a normal transvalvular flow rate (AVAproj) derived from dobutamine stress echocardiography (DSE) is superior to the traditional Doppler indices to discriminate true severe-AS and pseudosevere-AS. Purpose To compare two echocardiographic methods to estimate severity of LFLG AS with DSE (aortic valve area (AVA) estimated by continuity equation (AVA-CE) and simplified method of AVAproj) in patients (pts) with low transvalvular flow rate (<250mL/seg). Methods Unicentric, retrospective study, that included pts with LFLG AS undergoing DSE with low dose dobutamine protocol, during Nov 2013-Dec 2018 period. Evaluation at rest and peak DSE of vital signs, mean transaortic gradient, aortic VTI, LVOT VTI and VTI ratio, valvulo-arterial impedance (ZVA), AVA-CE, simplified method of AVAproj and global longitudinal strain (GLS). Results A total of 27 DSE were performed in 23 different pts, mean age of 76 ± 8 years, 82% male. At rest 55% in sinus rhythm, mean heart rate (HR) was 76 ± 12 bpm, mean systolic arterial pressure (SAP) was 122 ± 22 mmHg, mean ZVA 4.3 ± 2 mmHg/ml/m2; mean diameter of LVOT was 21,7 ± 2,6cm, mean of mean aortic gradients 21 ± 7 mmHg, 67% of pts had a VTI ratio at rest compatible with severe AS and remaining compatible with moderate AS. Estimated mean AVA-CE was 0.86 ± 0.29 cm2 with 67% of pts classified as severe AS. Mean left ventricular ejection fraction at rest was 31 ± 9%, systolic volume index 28,7 ± 8 mL/m2 and GLS -5,9%. During low dose perfusion protocol of dobutamine 100% patients remained asymptomatic, mean HR was 110 ± 25 bpm, mean SAP was 123 ± 26 mmHg, mean ZVA 3.6 ± 1.7 mmHg/mL/m2, mean of mean aortic gradients 28 ± 9mmHg, 37% of pts presented VTI ratio compatible with severe AS and remaining compatible with moderate AS. Mean flow reserve was 16 ± 16% and mean GLS-7.2%. AVA-CE was 1,06 ± 0,35 cm2 with 56% of pts classified as severe AS and mean projected AVA was 1.01 ± 0.22cm2, without significant difference in AVA estimated by the two methods (p = 0.344). Projected AVA allowed re-classification of AS in 22% of pts (5 patients), with 31% of severe AS reclassified as moderate AS while AVA-CE allowed re-classification in 13% (3 patients), with 19% of severe AS reclassified as moderate AS. Considering medium follow up of 24 months, 6 patients were submitted aortic valve replacement surgery and another 6 patients to transcatheter aortic valve replacement. The simplified projected valve area calculation show no significant therapeutic impact in the selection of this patients. Conclusion The simplified projected valve area calculation is technically feasible and accessible. This study shows a good correlation in pts with low cardiac flow. If AVAproj method had been used 2 extra patients would have been reclassified during DSE.

Improved right ventricular index of myocardial performance in the assessment of right ventricular function after coronary artery bypass grafting.

Decreased right ventricular (RV) longitudinal function following coronary artery bypass grafting (CABG), as assessed by tricuspid annular systolic excursion (TAPSE) and RV peak systolic velocity (RVS') is a known condition. We aimed to explore the feasibility of the right ventricular index of myocardial performance (RIMP) in the assessment of RV function after CABG at rest and during peak dobutamine stress echocardiography (DSE). Forty-two patients indicated for CABG were included in this study. Coronary angiography, DSE and exercise bicycle test were performed within 6 weeks before and 3 months after CABG. The RIMP, RVS' and TAPSE at the lateral tricuspid annulus were also assessed. The results were presented as mean ± standard deviation. The RIMP improved after CABG both at rest (0.45 ± 0.11 before vs 0.38 ± 0.08 after CABG, P = 0.013) and during DSE (0.75 ± 0.23 vs 0.49 ± 0.14, P < 0.001). TAPSE declined significantly when comparing the values from before CABG to after CABG both at rest (23.9 ± 4.46 vs 14.6 ± 3.67, P < 0.001) and during DSE (20.9 ± 4.16 vs 11.9 ± 3.60, P < 0.001). RVS' also decreased after CABG both at rest (11.9 ± 2.40 vs 8.5 ± 1.93, P < 0.001) and during DSE (15.6 ± 4.30 vs 10.5 ± 3.21, P < 0.001). On the other hand, exercise capacity improved after CABG compared with baseline (128.4 ± 40.12 W vs 142.1 ± 46.73 W, P = 0.014). RIMP improved after CABG both at rest and during DSE. The reduction in TAPSE and RVS' after CABG indicate reduced regional mechanical RV function along the long axis rather than reduced global RV function.

Prognostic value of dobutamine stress echocardiography in patients with myocardial dysfunction undergoing coronary artery bypass grafting

Background: Given the high capability of dobutamine stress echocardiography (DSE) in the actual estimation of the ventricular function and the prediction of the intraoperative or postoperative outcomes of revascularization, especially following coronary artery bypass grafting (CABG), we aimed to assess the relationship between DSE findings and CABG outcomes. Methods: This retrospective case–control study was conducted on forty patients with left ventricular (LV) systolic dysfunction who underwent CABG during an 8-year period. All the patients were assessed with DSE to determine their ventricular functional status. Checklists containing DSE findings based on the latest guideline, demographics, and the outcomes of revascularization were filled out for the participants. Telephone follow-up was done for all the participants after 6 months. The data were analyzed using SPSS, version 16. Results: Resting LV ejection fraction (LVEF) ≤25%, peak DSE LVEF ≤35%, absolute increase in the LVEF (LVEF change) 2.25, a minimum pulmonary artery pressure (PAP) of 30 mmHg, and nonviable myocardium had positive correlations with the short- and long-term complications of CABG. These correlations were statistically significant between a maximum pre-DSE LVEF of 25% and an LVEF change of

Coronary artery spasm and dobutamine stress echocardiography in patients without known coronary disease: prevalence, predictors and outcomes

Background and objective Given its high diagnostic and prognostic value and good safety profile, dobutamine stress echocardiography (DSE) is widely used in patients with known or suspected coronary artery disease (CAD); it may however, occasionally induce coronary vasospasm. In this study, we aimed to evaluate the prevalence of dobutamine-related coronary spasm in patients without known CAD, to determine the potential predictors of spasm amongst those with positive DSE and to assess mid-term clinical outcomes.Methods 3,952 patients referred to our echocardiography laboratory for DSE between January 2010 and May 2012 were prospectively investigated. Those with positive DSE underwent coronary angiograms with systematic methylergometrine intracoronary injection in case of absence of significant coronary stenosis or spontaneous occlusive coronary spasm. Patients with spontaneous occlusive coronary spasm or a positive methylergometrine test but no significant stenoses were enrolled and compared with those with positive DSE and significant coronary lesions at angiograms but no history of CAD.Results Twenty-nine patients with DSE-related vasospasm (19.4% of positive DSE without known CAD) were compared with 64 patients with significant coronary lesions. They were significantly younger (56 vs 67.7 years; P < 0.001), had less frequently hypertension (27.6% vs 64.1%; P = 0.01) and diabetes mellitus (31% vs 68.8%; P = 0.01); conversely they had more frequently dyslipidaemia (79.3% vs 53.1%; P = 0.021); they also had a lower ischaemic area at peak DSE (< 4 involved segments) at 79.3% vs 48.4% (P = 0.006). On multivariate analysis, dyslipidaemia (HR = 21.3; 95% CI = [3.45-131.7]; P = 0.001), and less than 4 ischaemic segments at peak DSE (HR = 4.3; 95% CI = [1.14-16.23]; P = 0.034) were found to be independent predictors of coronary spasm rather than significant coronary lesions. Conversely, hypertension, DM and age > 60 were predictors of significant coronary lesions rather than spasm. Long-term actuarial survival free from adverse events was significantly higher in the group of patients with coronary spasm at 93% versus 70% (log rank P = 0.037) in patients with significant coronary disease.Conclusion DSE-induced coronary spasm is an important condition associated with a good mid-term prognosis; dyslipidaemia and lower ischaemic area at peak DSE predicted spasm rather than significant stenoses in patients with positive DSE and no history of CAD.

Is left ventricular dysfunction reversed after complete alcohol abstinence in asymptomatic alcoholics? A tissue Doppler-derived strain and 2D strain imaging stress echocardiography study

ABSTRACT BACKGROUND: Long-term alcohol abuse exerts a deleterious effect on the myocardium, although clinical manifestations of alcoholic cardiomyopathy are not always present. In the present study we evaluate left ventricular (LV) dysfunction by means of tissue Doppler (TD) derived strain and 2D strain imaging stress echocardiography techniques in asymptomatic alcoholics and examine the reversibility ofLV dysfunction after complete abstinence from alcohol. METHODS AND RESULTS: In 13 chronic alcoholics (9 men, mean age 45±6 years) with mean alcohol consumption 207.7±98.3 g/day over 16.5±6.9 years, dobutamine stress echocardiography (DSE) was performed.LV deformation in 12 segments was assessed using TD velocity and strain and speckle tracking with 2D strain imaging, at baseline as well as at 5, 10, and 20 μg/kg/min stages of dobutamine infusion. The examinations were repeated one month after alcohol discontinuation. LV dimensions, wall thickness and ejection fraction were within normal limits. Grade I diastolic dysfunction was observed in 9 patients. During DSE peak TD systolic velocity was increased significantly in allLV myocardial segments, whereas TD strain and 2D strain did not change significantly in the majority of the myocardial segments. One month’s complete abstinence from alcohol did not lead to any noticeable improvement, since baseline and peak DSE, TD and 2D strain did not progress significantly. CONCLUSIONS: The lack of myocardial strain improvement during DSE may indicate early effects on the myocardium due to chronic alcohol abuse, before clinical manifestations are even present. No reversibility ofLV dysfunction was observed after complete abstinence from alcohol for one month.

Low-dose dobutamine stress echo for reverse remodeling prediction after cardiac resynchronization

PurposeCardiac resynchronization therapy (CRT) is a valuable option for patients with heart failure and wide QRS to reduce electromechanical dyssynchrony (DYS). High non-responders rate (30%) urges the need to improve selection of candidates for CRT. We hypothesized that low-dose dobutamine stress echocardiography (DSE) can help unmask dyssynchronous motion. The aim of this study is comparison between dyssynchrony index at rest and during low-dose dobutamine stress to predict left ventricular reverse remodeling after CRT. Patients and methodsProspectively, 57 consecutive patients (37 male) aged 61.8±9 who qualified for CRT according to current guidelines were enrolled. Two dimensional echocardiography and tissue Doppler imaging (TDI) were performed before and 6 month after CRT to assess reverse remodeling (rLV). Additionally DSE was performed before CRT. DYS was assessed at rest (DYSr) and peak DSE (DYSd) separately, as a difference between time to peak systolic velocity (Ts) of septum and lateral wall. Ts was corrected for heart rate. ResultsrLV defined as decrease ≥15% of LVESV at follow-up was found in 38 (67%) patients. DYSr and DYSd were independent predictors of rLV (OR=1.04, Cl ±1.02–1.06, p<0.02 and OR=1.05, Cl±1.03–1.08, p<0.0002 respectively). ROC analysis found that DYSr>42ms and DYSd>59ms had sensitivity of 70% and 87%, specificity of 61% and 78%, and accuracy of 70% and 84% respectively for prediction of reverse remodeling LV. Area under Receiver Operating Characteristic Curve for DYSd was higher than for DYSr (0.89 vs 0.71, p<0.007). ConclusionExercise intraventricular dyssynchrony assessed by dobutamine stress echo is a strong independent predictor of cardiac resynchronization therapy response.

Left Atrial Volume Index at Peak Dobutamine Stress Echocardiography Predicts the Extent of Coronary Artery Disease in Patients with Normal Resting Wall Motion

Left atrial volume indexed to body surface area (LAVI) measured at rest is an independent predictor of adverse cardiovascular outcome at long-term follow-up. We explored the value of LAVI measured at peak dobutamine stress echocardiography (DSE) to identify patients with significant coronary artery disease (CAD) and to discriminate those with multivessel CAD. We enrolled 100 patients of 134 consecutively screened patients without resting wall-motion abnormalities (WMA) referred for DSE. LA volume was measured using the biplane area-length method at rest and at peak DSE. Significant coronary stenosis was defined as ≥50% obstruction of ≥1 sizable artery by coronary angiography. The mean age was 57.2±10.6years (55% males). Fifty-six patients (56%) had significant CAD by coronary angiography: 28 (28%) had single-vessel CAD, and 28 (28%) had multivessel CAD. ROC curve analysis showed that the optimal cutoff value of stress-induced LAVI that best discriminates significant CAD was 30.1mL/m(2) . Using this cutoff value, significant CAD was identified with a sensitivity of 85.7%, specificity 95.5%, PPV 96%, and NPV 84%. The optimal cutoff value of stress-induced LAVI that best discriminates multivessel CAD was 32.7mL/m(2) . Using this cutoff value, multivessel CAD was identified with a sensitivity of 88.7%, specificity 96.5%, PPV 97%, and NPV 89%. In symptomatic patients who underwent DSE for suspected CAD and had no resting WMA, LAVI measured at peak DSE predicted angiographically significant CAD with acceptable sensitivity and high specificity and predicted multivessel CAD with high sensitivity and specificity.

0027: Dobutamine-related coronary spasm among patients with false positive dobutamine stress echocardiography: prevalence and predictors

Dobutamine stress echocardiography (DSE) is being consistently used as an exercise-independent stress modality aimed at the detection of coronary artery disease (CAD) and the evaluation of myocardial ischemia. It may though occasionally induce coronary vasospasm. In this study, we aimed to evaluate the prevalence and predictors of dobuta-mine-related coronary spasm in patients without known CAD and false positive DSE (positive DSE but no significant coronary lesions on angio-gram) 3952 patients referred to our echocardiography laboratory for DSE between January 2010 and May 2012 were prospectively investigated. Those with positive DSE underwent coronary angiograms with systematic methylergometrine intracoronary injection in case of absence of significant coronary stenosis or spontaneous occlusive coronary spasm. Patients with spontaneous occlusive coronary spasm or positive methylergometrine test but no significant stenoses were enrolled and compared with those with positive DSE but no coronary lesions nor spontaneous or induced spasm (« true » false positive DSE) 29 patients with DSE-related vasospasm (19.4% of positive DSE without known CAD) were compared with 56 patients with no lesions and no spam (« true » false positive DSE). They were more frequently smokers (72.4% vs 37.5%; p=0.003); they had more frequently dyslipidemia (79.3% vs 43%;p=0.001); they also had a larger ischemic area at peak DSE (3.4 vs 2.7 segments; p=0.05). On multivariate analysis, dyslipidemia (HR=10.7; 95% CI= [2.7-42.1]; p=0.001) and active smoking (HR=6.1; 95% CI= [1.7-21.1]; p=0.004) were found to be independant predictors of spam-related DSE rather than « true » false positive DSE. DSE- related coronary spasm is present in a significant proportion of patients with erroneously labelled « false » positive DSE and should systematically be ruled out. Dyslipidemia and active smoking were independant predictors of spasm rather than « true » false positive DSE

Oral Abstract session: Stress echo in clinical practice: Friday 5 December 2014, 08:30-10:00 * Location: Agora

Oral Abstract session: Stress echo in clinical practice: Friday 5 December 2014, 08:30-10:00 * Location: Agora

Global Myocardial Contractile Reserve Assessed by High‐Dose Dobutamine Stress Echocardiography Predicts Response to the Cardiac Resynchronization Therapy

Myocardial contractile reserve (CR) is a strong prognostic factor in patients with heart failure. The presence of significant myocardial fibrosis can lead to a reduced response to cardiac resynchronization therapy (CRT). We assumed that myocardial CR assessed by high-dose dobutamine stress echocardiography (DSE) would predict response to CRT. Fifty-two consecutive symptomatic patients with heart failure (New York Heart Association [NYHA] class III), with depressed ejection fraction (EF) of the left ventricle (26.3 ± 6.9%) and dyssynchronous contractions (QRS duration 149.8 ± 23.8 msec) underwent DSE before CRT implantation. The difference in EF at rest and at peak (40 μg/kg per minute) DSE indicated global CR. Responders to CRT were defined by a decrease in left ventricular end-systolic volume of ≥15% and/or an increase in EF of ≥5% after 6 months of CRT. During high-dose dobutamine infusion, responders (28 patients, 54%) showed a greater increase in EF compared with nonresponders (Δ 11 ± 7% vs. Δ 2 ± 9%, P = 0.007). CR correlated moderately with an improvement in EF after 6 months of CRT (r = 0.50, P = 0.0009). Furthermore, responders showed significant improvement in clinical status, evaluated by a reduction in NYHA functional class (-0.8 ± 0.6 vs. 0.1 ± 0.4, P = 0.02), compared with nonresponders. A 7% exercise-induced increase in EF yielded sensitivity of 79% and specificity of 87% in predicting the response to CRT after 6 months. Myocardial CR assessed by high-dose DSE can play a potentially important role in identifying responders to CRT.

Feasibility of Myocardial Performance Index for Evaluation of Left Ventricular Function during Dobutamine Stress Echocardiography before and after Coronary Artery Bypass Grafting

Myocardial performance index (MPI) is a measure of combined systolic and diastolic myocardial function. In patients with coronary artery disease (CAD) an increase in MPI is consistent with myocardial dysfunction. The objectives of this study were to characterize the changes in MPI after coronary artery bypass graft (CABG) at rest and at peak dobutamine stress echocardiography (DSE). Thirty-six patients diagnosed with CAD and accepted for CABG were studied by standard echocardiography and DSE 1month prior and 3month after CABG. The MPI was calculated using pulsed-wave tissue Doppler imaging (PW-TDI) of the left ventricular (LV) wall-motion velocity. At baseline, ejection fraction (EF; 42.7±8%) and wall-motion score index (WMSI; 1.1±0.2) were impaired at rest as well as at peak DSE (EF; 49.2±9 and WMSI 1.4±0.2). MPI was prolonged both at rest (0.61±0.13) and at peak DSE (0.78±0.16). After CABG, EF and WMSI did not improve at rest (43.7±8% and 1.1±0.2, respectively). On the other hand, MPI improved substantially both at rest (0.45±0.08; P<0.001) and at peak DSE (0.56±0.1; P<0.001). At peak DSE an improvement of EF (54.2±9; P<0.05) and WMSI (1.1±0.16; P<0.001) was seen as well. Myocardial performance index shows significant improvement after CABG in patients with CAD both at rest and peak DSE and appears to be a sensitive measure of myocardial function.

Long-Term Prognostic Impact of Dobutamine Stress Echocardiography in Patients With Kawasaki Disease and Coronary Artery Lesions: A 15-Year Follow-Up Study

This study sought to determine the prognostic value of dobutamine stress echocardiography (DSE) over a 15-year follow-up for predicting cardiac events in adolescent Kawasaki disease (KD) patients with coronary artery lesions (CALs). Although DSE is an established technique for the detection of coronary artery disease, its prognostic value to predict cardiac events in adolescent KD patients with CALs is unknown. Fifty-eight adolescent KD patients, including 36 patients with CALs documented by coronary angiography, and 22 patients with normal coronary arteries documented by echocardiography who underwent DSE were reviewed at initial testing (mean age: 13.6 years) and at 15 years' follow-up. Follow-up events were tabulated as major adverse cardiac events (MACEs) that included cardiac death, nonfatal myocardial infarction, and revascularization. During a mean follow-up of 14.7 years, there were 16 patients with MACEs (acute myocardial infarction: n = 1; old myocardial infarction: n = 7; coronary artery bypass grafting: n = 4; percutaneous coronary intervention: n = 4). Significant coronary artery disease (CAD) (>70% coronary stenosis) was detected in 31.0% of patients at initial testing and 42.1% at follow-up. However, there were no significant differences in wall motion score indices (WMSI) at peak DSE between initial testing and follow-up (p= 0.762). Five of 6 patients (85%) with false-positive DSE results (WMSI:≥1.25) at initial testing, who had giant aneurysms without CAD, developed CAD with MACEs during follow-up. Cumulative event-free survival rate to 15 years was 25.0% in patients with WMSI≥1.25 and 91.7% in patients with WMSI<1.25. Cox regression analysis showed the grade of peak WMSI at initial testing to be the only independent predictor of MACEs (relative risk: 3.28; 95% confidence interval: 1.73 to 6.20). DSE provided independent prognostic information up to 15 years in adolescent KD survivors.

Tissue Doppler systolic velocity change during dobutamine stress echocardiography predicts contractile reserve and exercise tolerance in patients with heart failure

Dobutamine stress echocardiography (DSE) is widely used to evaluate myocardial contractile reserve in patients with heart failure (HF). The aim of the study was to assess the relationship between the tissue Doppler (TD) mitral annulus systolic velocity (Sm) change during DSE, contractile reserve, and aerobic exercise capacity in HF patients. Sixty-four HF patients (age 67 ± 9 years, 58% with an ischaemic aetiology, and a mean value of the ejection fraction 29 ± 7%) underwent high-dose DSE. The mean value of the TD mitral annulus septal-lateral Sm change was analysed at rest and at peak DSE. All patients underwent also the cardiopulmonary exercise test. With a receiver operating characteristic analysis, a value of 2.02 cm/s obtained as a stress-rest difference in a mean value of the peak systolic velocity of the mitral annulus (Sm) was the best value for diagnosing the myocardial contractile reserve [area under the curve 0.69 (95% CI 0.56-0.80), sensitivity 69% (95% CI 54-81), specificity 80% (95% CI 45-97)]. The patient population was divided into two groups: with rest-stress Sm change during DSE ≤ 2.02 cm/s and with rest-stress Sm change >2.02 cm/s. Patients with Sm rest-stress >2.02 change during DSE, compared with patients with rest-stress change ≤2.02, showed a lower incidence of severe diastolic dysfunction at rest (16 vs. 46%, P= 0.039) and lower E/Ea values (11 ± 5 vs. 15 ± 6, P = 0.005), similar ejection fraction at rest but higher ejection fraction at peak DSE (53 ± 14 vs. 41 ± 12%, P = 0.001), better myocardial contractile reserve assessed by a pressure-volume relationship (1.89 ± 2.01 vs. 0.58 ± 1.38 mmHg/mL/m(2), P = 0.004), with a lower end-systolic volume (-46 ± 20 vs. -24 ± 19%, P< 0.001), a higher increase in the ejection fraction (23 ± 10 vs. 12 ± 10%, P = 0.001) during DSE, and better peak oxygen consumption (16 ± 4 vs. 13 ± 2 mL/kg/min, P = 0.01). In patients with HF, the rest-stress variation of mitral annulus systolic velocities during DSE predicts the presence of myocardial contractile reserve and exercise tolerance.

Prognostic Value of Exercise Stress Test and Dobutamine Stress Echo in Patients with Known Coronary Artery Disease

The aim of this study was to compare the feasibility of dobutamine stress echocardiography (DSE) and exercise stress test (EST) between patients in different age groups and to evaluate their proportional prognostic value in a population with established coronary artery disease (CAD). The study sample included 323 subjects, subdivided in group 1 (G1), comprising 246 patients aged <75 years, and group 2 (G2), with 77 subjects aged >or=75 years. DSE and EST were performed before enrollment in a cardiac rehabilitation program; for prognostic assessment, end points were all-cause mortality and hard cardiac events (cardiac death or nonfatal myocardial infarction). During DSE, G2 patients showed worse wall motion score index (WMSI), but the test was stopped for complications in a comparable proportion of cases (54 G1 and 19 G2 patients, P = NS). EST was inconclusive in similarly high proportion of patients in both groups (76% in G1 vs. 84% in G2, P = NS); G2 patients reached a significantly lower total workload (6 +/- 1.6 METs in G1 vs. 5 +/- 1.2 METs in G2, P < 0.001). At multivariate analysis, a lower peak exercise capacity (HR 0.566, CI 0.351-0.914, P = 0.020) was associated with higher mortality, while a high-dose WMSI >2 (HR 5.123, CI 1.559-16.833, P = 0.007), viability (HR 3.354, CI 1.162-9.678, P = 0.025), and nonprescription of beta-blockers (HR 0.328, CI 0.114-0.945, P = 0.039) predicted hard cardiac events. In patients with known CAD, EST and DSE maintain a significant prognostic role in terms of peak exercise capacity for EST and of presence of viability and an extensive wall motion abnormalities at peak DSE.

Abstract 4228: Objective Judgment in Dobutamine Stress Echocardiography: Visualization of Post-Systolic Shortening by Tissue Doppler Imaging

Background: Although dobutamine stress echocardiography (DSE) is widely used for the detection of coronary artery disease (CAD), interpretation requires expertise. Post-systolic shortening (PSS) is a sensitive maker of myocardial ischemia. We have developed a novel tissue Doppler imaging (TDI) technique that readily visualizes the presence of PSS on 2-dimensional echocardiograms, and investigated whether CAD is objectively detectable by using this technique during DSE. Methods: Detection of diastolic abnormality by displacement Imaging (DADI): PSS was detected by using tissue Doppler displacement timing analysis. In this method, end-systole was automatically determined from tissue velocity, and delays of the displacement peaks from the end-systole were displayed from green to red on the left ventricular apical views, depending on the preset time window. DSE was performed in consecutive 51 patients prior to coronary angiography (CAG) who underwent diagnostic CAG for suspected CAD, and presented with normal LV wall motion at rest (male=31, age ranged 44 – 83 years). We measured the time from the end-systole to displacement peak (ΔT) at each segment in the apical, mid and basal segments by the standard apical plane (long axis, 4 chamber and 2 chamber views). The optimal cut-off value of ΔT for discriminating normal from CAD was determined by receiver operating characteristic analysis. Finally, DADI was performed using the optimal ΔT. CAD was confirmed by CAG as having &gt;75% diameter stenosis. Results: Angiographic CAD was present in 31 patients (61%). DADI predicted CAD with sensitivity of 87%, specificity of 75%, negative predictive value of 79%, and predictive accuracy of 82% at the cut-ff ΔT of 80 ms at peak DSE. Conclusion: DADI was useful in making objective judgment in DSE by readily portraying the presence of PSS, a marker of myocardial ischemia, on 2-dimensional echocardiograms in patients with inducible myocardial ischemia.

Predictors of Outcomes in Low-Flow, Low-Gradient Aortic Stenosis

Patients with low-flow, low-gradient aortic stenosis have a poor prognosis with conservative therapy but a high operative mortality if treated surgically. Recently, we proposed a new index of aortic stenosis severity derived from dobutamine stress echocardiography, the projected aortic valve area at a normal transvalvular flow rate, as superior to other conventional indices to differentiate true-severe from pseudosevere aortic stenosis. The objective of this study was to identify the determinants of survival, functional status, and change in left ventricular ejection fraction during follow-up of patients with low-flow, low-gradient aortic stenosis. One hundred one patients with low-flow, low-gradient aortic stenosis (aortic valve area </=1.2 cm(2), left ventricular ejection fraction </=40%, and mean gradient </=40 mm Hg) underwent dobutamine stress echocardiography and an assessment of functional capacity using the Duke Activity Status Index. A subset of 72 patients also underwent a 6-minute walk test. Overall survival was 70+/-5% at 1 year and 57+/-6% at 3 years. After adjusting for age, gender, and the type of treatment (aortic valve replacement versus no aortic valve replacement), significant predictors of mortality during follow-up were a Duke Activity Status Index </=20 (P=0.0005) or 6-minute walk test distance </=320 m (P<0.0001, in the subset of 72 patients), projected aortic valve area at a normal transvalvular flow rate </=1.2 cm(2) (P=0.03), and peak dobutamine stress echocardiography left ventricular ejection fraction </=35% (P=0.03). More severe stenosis, defined as projected aortic valve area </=1.2 cm(2), was a predictor of mortality only in the no aortic valve replacement group. The Duke Activity Status Index, 6-minute walk test, and left ventricular ejection fraction improved significantly during follow-up in the aortic valve replacement group, but remained unchanged or decreased in the no aortic valve replacement group. In patients with low-flow, low-gradient aortic stenosis, the most significant risk factors for poor outcome were (1) impaired functional capacity as measured by Duke Activity Status Index or 6-minute walk test distance; (2) more severe valve stenosis as measured by projected aortic valve area at a normal transvalvular flow rate; and (3) reduced peak stress left ventricular ejection fraction, a composite measure accounting for both resting left ventricular function and contractile reserve.

Abstract 2062: Predictors Of Outcome In Low Flow, Low Gradient Aortic Stenosis. Result Of The Multicenter Topas Study

Background: Patients with low flow aortic stenosis (AS) have a poor prognosis and a high operative mortality. Dobutamine stress echocardiography (DSE) has been used to assess LV contractile reserve and determine the “actual” severity of the stenosis. Recently, we proposed the projected aortic valve area at a normal flow rate (AVA proj ) to better differentiate true-severe from pseudo-severe AS. The objective of this study was to identify the independent predictors of survival in low flow, low gradient AS. Methods and results: 101 patients with low flow, low gradient AS (AVA≤1.2cm 2 , LV Ejection Fraction (LVEF) ≤40% and mean gradient (MG) ≤40 mmHg) underwent DSE and an assessment of functional capacity using the Duke Activity Status Index (DASI). A subgroup of 74 patients underwent a 6-minute walk test (6MWT). Overall survival was 70±5% at 1 year and 61±5% at 2 years. On univariate analysis, predictors of mortality were 6MWT ≤320m (p&lt;0.0001), DASI ≤20 (p=0.0001), rest AVA ≤1cm 2 p=(0.006), peak DSE LVEF (LVEF peak ) ≤35% (p=0.02), AVA proj ≤1.2cm 2 (p=0.04). After adjusting for age, gender, and the type of treatment (surgical vs. medical), significant predictors of mortality were DASI ≤20 (HR: 1.79, 95%CI: 1.28 –2.53 p=0.0006) and AVA proj ≤1.2cm 2 (HR:1.64, 95%CI: 1.04 –2.87 p=0.03). In the subgroup of patients undergoing a 6MWT (n=74), independent predictors of mortality were: 6MWT ≤320m (HR: 2.49, 95%CI: 1.55– 4.30 p&lt;0.0001), AVA proj ≤1.2cm 2 (HR: 2.07, 95%CI: 1.18 – 4.08 p=0.01), and LVEF peak ≤35% (HR: 1.64, 95%CI: 1.10 –2.51 p=0.016). In the subset of patients undergoing valve replacement (n=44), unvariate predictors of operative mortality (18%) were: 6MWT ≤180m (OR: 9.8, 95%CI: 3.7–35, p=0.0002), DASI ≤15 (OR: 3.21, 95%CI: 1.67– 6.48, p=0.011) and LVEF peak ≤20% (HR:5.83, 95%CI: 2.6 –16.7 p=0.001). Conclusion: In low flow, low gradient AS, the most significant risk factors for poor outcome were: Impaired functional capacity documented by a reduced DASI or 6MWT, More severe valve stenosis as documented by a smaller AVA proj , and Reduced peak stress LVEF, a composite accounting for resting LV function and contractile reserve. This new knowledge may assist in predicting the prognosis of patients with low flow AS and improve operative risk stratification.

The value of contrast dobutamine stress echocardiography in detecting coronary artery disease in overweight and obese patients

Dobutamine stress echocardiography (DSE) is an established method of detecting myocardial ischemia. Its diagnostic accuracy solely depends on wall motion assessment. Clear visibility of the left ventricular endocardium is essential for reliable assessment of a wall motion abnormality. However, incremental benefits of contrast DSE for the detection of coronary artery disease (CAD) have not been demonstrated in overweight or obese patients. The purpose of the present study was to test the incremental benefits of contrast DSE in detecting CAD in overweight or obese patients. Sixty-two overweight or obese patients (body mass index 26 kg/m(2) to 33 kg/m(2)) underwent DSE with or without contrast and coronary angiography. Contrast-enhanced images were achieved at rest and during peak DSE after administration of SonoVue (Bracco Diagnostics Inc, Italy) or Optison (Mallinckrodt, USA). The endocardial border resolution for each myocardial segment was graded as 0, 1 or 2. A total of 992 segments from 62 subjects were analyzed. The results of DSE with or without contrast were compared with the findings on angiography. The differences in the score grading between the two groups with or without contrast, at rest and during peak DSE were statistically significant (P<0.001). The sensitivity, specificity and accuracy of contrast DSE in detecting CAD, compared with the studies without contrast, were improved (82% versus 70%, 78% versus 67% and 81% versus 69%, respectively). SonoVue and Optison can enhance left ventricular endocardial border delineation in overweight or obese patients, optimizing the evaluation of wall motion both at rest and during peak stress. This increases the diagnostic value of DSE in detecting CAD.

The long prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography after receiving acute β-blockade

To assess the prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography in addition to wall motion abnormalities at peak stress. Wall motion abnormalities were assessed at peak and during recovery phase of dobutamine stress echocardiography in 187 consecutive patients, who were followed for occurrence of cardiac events. During follow-up (mean 36+/-28 months), 19 patients (10%) died from cardiac causes, 34 (18%) patients suffered nonfatal myocardial infarction, and 77 (41%) patients underwent late revascularization. Univariable predictors of cardiac events by Cox regression analysis were age (hazard ratio: 1.01; confidence interval: 1.00-1.03), dyslipidemia (hazard ratio: 1.41; confidence interval: 1.02-1.95), rest wall motion abnormalities (hazard ratio: 1.37; confidence interval: 1.14-1.64), new wall motion abnormalities (hazard ratio: 1.18; confidence interval: 0.95-1.45) at peak and new wall motion abnormalities (hazard ratio: 1.33; confidence interval: 1.11-1.59) at recovery phase of dobutamine stress echocardiography. The best multivariable model to predict cardiac events included new wall motion abnormality (hazard ratio: 5.34; confidence interval: 1.71-16.59) at recovery phase of dobutamine stress echocardiography, after controlling for clinical and peak dobutamine stress echocardiography data. Myocardial ischemia at recovery phase of dobutamine stress echocardiography is an independent predictor of cardiac events and has an incremental value when added to ischemia at peak.

Prognostic Significance of Akinesis Becoming Dyskinesis During Dobutamine Stress Echocardiography

Akinesis becoming dyskinesis (AKBD) at high-dose dobutamine stress echocardiography (DSE) has been disregarded as a marker of myocardial ischemia. However, its prognostic significance is unknown. We sought to assess the long-term outcome of patients with AKBD during DSE. A total of 731 patients (age 62 +/- 15 years, 628 men) with two or more akinetic left ventricular segments at rest underwent DSE and were followed up for a mean period of 5 +/- 2.7 years. The end points considered during follow-up were hard cardiac events (cardiac death and nonfatal myocardial infarction) and heart failure. Dyskinesis in two or more segments at peak stress developed in 60 patients (8%). Resting wall-motion score index was 2.6 +/- 0.56 in patients with AKBD versus 2.3 +/- 0.55 in patients without AKBD (P = .0002). Ischemia occurred in 197 patients (27%). During follow-up, 254 patients (35%) developed hard cardiac events and 204 patients (28%) developed heart failure. In all, 226 patients (31%) died of various causes (cardiac death in 172 patients). The annualized hard cardiac event rate was 11% in patients with AKBD and 6% in patients without (P = .03). The incidence of heart failure was significantly higher in patients with AKBD than without (47% vs 26%, P < .001). Independent predictors of hard cardiac events were age (hazard ratio [HR] 1.03 [confidence interval {CI} = 1.01-1.04]), previous myocardial infarction (HR 1.4 [CI = 1.1-1.9]), diabetes mellitus (HR 1.8 [CI = 1.3-2.5]), resting wall-motion score index (HR 1.11 [CI = 1.01-1.04]), and AKBD (HR 1.6 [CI = 1.1-2.4]). AKBD at peak DSE is associated with increased risk of cardiac events in patients with akinetic segments at baseline echocardiogram.